The present invention relates to a fuel control valve located in a fuel tank.
A conventional fuel control valve, as shown in FIGS. 3, 4, is disclosed in a Japanese Utility Model Publication No.5(1993)-25309. Referring to FIG. 3, a pipe 109 has a fluid communication with a fuel tank 100 for a motor vehicle (not shown). A nozzle 110 is inserted into an upper end of the pipe 109 and supplies a fuel (gasoline and so on) into the tank 100. A sensor 111 is fixed to the pipe 109 and detects an insertion of the nozzle 110.
Ventilation pipe 104 has a fluid communication with a vapor portion 101 of the tank 100. Even though the tank 100 is filled up! by the fuel, fuel vapor exists in the vapor portion 101. A check valve 102 and a canister 103 are located in the pipe 104. The check valve 102 keeps an inner pressure of the tank 100 constant. The fuel vapor in the tank 100 is absorbed by the canister 103 via the pipe 104, mainly when the vehicle runs or stops.
Ventilation pipe 107 also has fluid communication with the tank 100. A fuel control valve 108 located in the tank 100 is fixed to a lower end of the pipe 107 extending into the tank 100. A solenoid valve 105 and a canister 106 are located in the pipe 107. When fuel is supplied into the tank 100, a large amount of fuel vapor is generated in the tank 100. Thus, the valve 105 is opened when the sensor 111 detects the insertion of the nozzle 110. The large amount of fuel vapor in the tank 100 is absorbed by the canister 106 via the pipe 107.
Referring to FIG. 4, the fuel control valve 108 is specifically shown. The valve 108 comprises a cup-shaped body 120, a cover 121 and a float 123. Liquid passages 125 are formed on a bottom of the body 120. An upper opening of the body 120 is closed by the cover 122. The lower end of the pipe 107 is inserted into an outlet 122 of the cover 121. A tapered seat 129 of the cover 121 is formed continuously with the outlet 122. A spherical head of the float 123 is engageable with the tapered seat 129. Vapor inlets 124 are formed in the tapered seat 129. A horizontal flange 126 is formed on lower end of the inlets 124. A fuel passage 128 is formed between the inlets 124 and the outlet 122 when the float is spaced apart from the seat 129.
When fuel is supplied into the tank 100, the fuel level in the tank 100 is lower than the position of the float 123. Thus, the float 123 is spaced from the seat 129 and a large amount of fuel vapor flows from the inlets 124 to the outlet 122 through the passage 128. When the tank 100 is filled up, the float 123 presses on the seat 129. As a result, the passage 128 is shut off.
As the vehicle consumes the fuel in the tank 100, the fuel level therein becomes low. As a result, the float 123 becomes spaced apart from the seat 129 again. When the vehicle runs on, the vehicle and the tank 100 vibrate. Therefore, fuel in the tank 100 splashes about and drops of the fuel flow to outlet 122 over the flange 126.